""" 
CSDN : heart_6662
PYTHON amateur   
"""
if __name__ == '__main__':
    a = [9,6,5,4,1]
    n = len(a)
    print(a)
    for i in range(len(a)//2):
        a[i],a[n-i-1] = a[n-i-1],a[i]
    print(a)